Most persons having an interest in photography are familiar with mounting corners provided with securing means on the rear side thereof, that have been used for many decades in the mounting of photographs, pictures and the like, and by way of illustration, the Murray U.S. Pat. No. 1,194,217 of Aug. 8, 1916 pertains to the use of corner pockets 14 " . . . constructed from any suitable material . . . ." Provided on the rear face of each corner pocket 14 of Murray is a stick pin 15. As pointed out by this patentee, attachment is accomplished by the points being forced into " . . . the wall of the standing structure . . . ", and this reference pertains to no mounting means other than the use of the sharpened point.
By remarking that his corner pockets 14 can be "constructed from any suitable material," Murray manifestly does not have in mind the use of mounting corners " . . . constructed from relatively thick, rigid material . . . ," as is involved in the present invention.
Regarding the embodiment of our invention directed to the use of magnetic means for securing the magnetic corners to surfaces of ferric material, the Bliss U.S. Pat. No. 1,516,264 utilizes U-shaped magnets of substantial size, clearly intended to be used in a central portion of the backside of a picture. Bliss' magnets are not in any manner adaptable for the use on the backside of triangularly shaped mounting corners of rigid construction, and the Bliss concept would not appear to logically be able to be transferred to a teaching directed to the construction of mounting corners.
A prior art patent more directly illustrative of mounting corners is the Flood U.S. Pat. No. 2,825,166 entitled "Strip of Corner Mount for Mounting Pictures and the Like," which issued Mar. 4, 1958, and another relevant patent is the Milos U.S. Pat. No. 3,346,979 entitled "Combined Negative and Photograph Corner Mounting," which issued Oct. 17, 1967. Both of these patents pertain to mounting corners involving the use of relatively flexible material.
A corner mount of a different character is set forth in the Parr, Jr. U.S. Pat. No. 4,179,089 entitled "Apertured Panel Corner Mount Fastener for Concrete Walls," which issued Dec. 18, 1979. This patent involves the use of relatively rigid material, but it contains a series of pins that the user is to drive into a concrete wall or the like. Like the others, the Parr teaching is of no particular consequence to the instant invention.
The Good U.S. Pat. No. 4,785,562 entitled "Magnetic Display Holder" teaches the display of sheet material such as a child's drawing, a sheet of scheduled events, photographs or the like upon a metal surface, such as a refrigerator door. The units proposed by Good are designed to hold photographs by retaining the photo between the frame and the metal surface. One would have to use Good's "L" framed units to display a photograph or any material with a stiffness factor greater than most photographs.
Flexible sheets of display material such as typing paper, coloring book sheets, newspaper articles or the like, can be mounted in the frame represented by Good's FIG. 2. To use the frame represented by his FIG. 2, the display material would have to be cut to the size of the frame and be flexible enough to have the corners inserted into the corner slots. If the display sheet is not flexible enough, damage to the display sheet will be caused by bending the corners into the slots, or else the material will hold the frame away from the metal surface, which would cause the magnetic properties of the frame to be ineffective.
The section frame as represented in Good's FIGS. 4a, 4b, 4c and 4d has the advantage of accommodating display material of different sizes. It also has the disadvantages of the frame in accordance with Good's FIG. 2, for the display material must be flexible enough to have the corners folded into the corner slots such as not to crease or damage the material. Also, if the material is somewhat thicker, such as most photo material or photos with backing material or posterboard, the sectional corners cannot compensate for the thicker display material inserted in the slots at the necessary angles, thereby defeating the entire purpose behind the use of the magnetic units. The Good invention is thus very limited in its tolerance for display materials of any significant thickness.
In view of the fact that in each of Good's embodiments, a magnet is utilized in close association with a corner section of considerable size, a substantial amount of expense as well as packaging difficulties will necessarily be involved in the use of the Good device.
It was in an effort to improve upon these and other such devices of the prior art, and to expand the use of mounting corners, that the present invention was created.